Saying NO and STOP is a universal sign. This is the first sign you show when you want to protect yourself. As a practicing therapist I know from my private practice that saying no is one of the most important skill in one's life. Even though the painting says so, I wasn't a paparazzo. :-) Kwab, my model let me paint him and I am grateful for that. The challenge was the foreshortening...
Sorry has a bad dog look... 'I wasn't so bad, don't be so angry' ...
You might know this look your dog had made a mess in your bed even though it was a forbidden territory for them...
This is Happy here. He is a great teacher of happiness. Really. There are many dogs with slight sadness in their 'personality'. Happy is just not that kind of dog. He knows how to live life the fullest, he is energetic and happy, happy, happy.